Homework 1

Introduction

This is our first R markdown document. In this section we will do a quick introduction about Japanese culture followed by a video and a text to explain what we think bout it. As you will see in the third section their will be a presentaion of what each person likes the most for example with Jetnisa it will be japanese culture and for Mehdi will be Arthur Conan Doyle and so on so forth. We will finish the assignement with R syntax and references that we used for our work.

Let’s take a look !

This is an introductory video aout Japan. A presentaion of common things in japan followed by a background explication. Of course there is much more to see in Jpan but there is always a starting point !

Group Members

Jetnisa

Voyage de Chihiro Poster

Voyage de Chihiro aka Spirited away

Quote of Miyazaki

The creation of a single world comes from a huge number of fragments and chaos.- Hayato Miyazaki

Emojis

## 😄

## 💠

## ❤️

Big GIF

Voyage de Chihiro

small GIF

My classes this semester

This table contains all the classes I am following this semester and the hours of each class.

Courses	Hours
Web based data collection	2:00
Microeconomics2	4:00
Sécurité des systèmes d’info	2:00
Création d’entreprise	2:00
Préjugés à l’université	2:00

Mehdi

Sherlock Holmes caption

Sherlock Holmes

Arthur Conan Doyle quotes :

When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth

Emojis

## 🧟

## ⚕️

## 🛫

Will give at random an emoji + To use chunk code: Cmd + Option + I

Large giphy

In front of statistical language

Small giphy

Table

Class	Hours
Web data	2H
Terrorisme	4H
Econ histoire	4H
Dev economics	4H
Sys inf sec	2H

Rachel

.

. .

Neila

. . . .

R Markdown Syntax

Misleading answers by using the cache option

(a <- runif(1))

## [1] 0.518656

we putted a being equal to some random uniform number

(d <- 2*a)

## [1] 1.037312

It should give the right answer

(d <- 2*a)

## [1] 1.037312

However when you change again the value of a, since by the cache function R stores the old value of a. To fix this problem we need to add another comment on the chunk code which is dependson. This will tell the program to take the value of a an not the saved one. Cahce can be very useful to save computaional time.

Random sample

n = 100
x = rnorm(n) # Generates 100 random numbers and stored in a vector
(median(x))

## [1] 0.1331012

(mean(x))

## [1] -0.06093101

(var(x))

## [1] 0.909801

It is normal to get values different from waht expected as n is not bug enough. As n grows we will get values close to the predicted ones.As e can see by changing the n = 100000 below

n = 100000
x = rnorm(n) # Generates 100000 random numbers and stored in a vector
(median(x))

## [1] 0.002625436

(mean(x))

## [1] 0.0008119247

(var(x))

## [1] 0.9873322

Histogram

b = 100
x = rnorm(b) # Generates 100 random numbers and stored in a vector
hist(x)

References